The field of the present invention is turbo-machinery, and more specifically, small, self-contained turboexpanders.
Turbine driven electrical generators have been employed for the generation of electric power in remote locations and under circumstances where electric power is not available from other sources. On offshore platforms and other locations where a source of pressurized gas is available, such devices may be driven by this source of energy. These turbines in turn drive an electric generator as a source of local power. Such machinery tends to be complicated, requiring outside control, lubrication, and buffer gas systems. Maintenance requirements are often substantial; and such systems tend to be large. In remote locations such as oil fields and offshore platforms, excessive size, complicated mechanisms and significant maintenance can be disadvantages.
Turbines have also been developed which employ a lubricant pump mechanically driven by the shaft of the turbine rotor for internal lubrication. One such system is illustrated in U.S. Pat. No. 2,804,021. A lubricant pump is coupled on the same shaft as a turbine rotor with that pump lubricating bearings rotatably mounting the shaft. Pressure on the lubricant but for the output from the pump is controlled by leakage pressure from the working fluid in the turbine. The reservoir of lubricant provides a self priming function when the turbine and pump are not rotating.